Telephone-exchange system



Jan. 20; 1925., 1,523,428

C. W. KECKLER TELEPHONE EXCHANGE SYSTEM Filed Dec. 31, 1919 //7 venfor:

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Patented Jan. 20, 1925.

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CHAR-LES W. KECKLER, OF NEVIARK, NEVT JERSEY, ASSIGNOR T WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed December 31, 1919.

To all whom it may concern:

Be it known that 1, CHARLES Knox;- LER, a citizen of the United States, residing at Newark, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telephone-EX- change Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to the means for disconnecting an impulse sender from a link circuit in a semi-automatic telephone exchange system.

This invention is adapted for use in a system in which calls are received in a manual switchboard and from there extended by an operator through automatic switches to a called line in an automatic exchange. In such a system the operator at the switchboard has an impulse sender for transmitting impulses through link circuits to control the automatic switches. Manual means are provided for associating the impulse sender with any desired link circuit.

An object of the invention is to provide improved means for disconnecting the imulse sender from the link circuit with which it has been associated.

To attain this object in accordance with one feature of the invention a mechanism associated with the impulse sender is provided which operates to automatically disconnect the impulse sender from the link circuit when a certain interval of time has elapsed after the impulse sender has been connected to a link circuit and is in its normal position.

A further feature is the provision of means for manually disconnecting the impulse sender from the link circuit with which it has been associated and connecting it to another link circuit, if it is desired to use the impulse sender before the automatic disconnection has been effected.

A still further feature is the provision of a signal at the operators position for indicating whether the impulse sender is connected to a link circuit.

These and other features not specifically mentioned above will more clearly appear from the following specification and the accompanying drawing which illustrates one embodiment of the invention.

There is shown in the drawing a telephone line A terminating in a ack in a manual switchboard.

Serial No. 348,581.

There is also shown located at the manual switchboard two link circuits B and C which are similarly equipped; hence similar apparatus in each link circuit will be designated by the same reference characters. A trunk line D terininatlng in a jack 12 at the switchboard cX- tends to an automatic exchange and terminates thereat in an ordinary line or trunk finder F which has access to connectors such as G. An automatic subscribers station is shown at- E, terminating in the contact bank of the connector switch G. These switches may be of any well known type and it is not thought necessary to fully illustrate the same in the drawing.

For the purpose of clearness, that portion of the circuit arrangement which niav be common to a plurality of link circuits is shown below the line OO. An impulse sender S may be connected to any one of a plurality of link circuits, such as B or G. by the actuation of a non-lockink key individual to the link circuit, which lights a pilot lamp L7, indicating to the operator that the impulse sender is connected. Manual means individual to the link circuits and automatic means common to the link circuits are provided for disconnecting the im pulse sender from the link circuit. Actuation of the key 20 energizes a relay such as 21 which connects the impulse sender to the calling end of the link circuit.

The automatic means for disconnecting the impulse sender may comprise a motor 24: having a shaft to which a plurality of angularly displaced cams, such as 3O, 31 and 32, are suitably fixed. Cooperating with each cam, such as 30, is a roller 33 suitablv held by a spring The spring 3% closes 21 set of contacts when the roller 38 comes in contact with the operative surface of the cam, and these contacts cooperating with their associated relay and relay 4:6 serve to effect the disconnection of the impulse sender S.

The operation of the automatic disconnection is such that if the operator fails to dial after connecting the impulse sender S to a cord circuit or after completion of dialing. the impulse sender S will be automaticallv disconnected when a certain time interval has elapsed. This interval may be fixed as desired, for example, it may be three or five seconds, and depends upon the elapsed time between two successive closures of the contact set whose associated relay has been operated. The speed of the motor and the size of the cam may be as desired, thereby fixing this interval.

It is thought that the invention may be more fully comprehended from the following description of the operation of the system shown in the drawing,

Assuming that the subscriber at station A has initiated a call in the usual manner, the operator in answering inserts answering plug 6 of an idle link circuit, such as B, into jack of the line of station A. Line signal 7 is thereupon disconnected from the line A and supervisory relay '8 of the link circuit is energized over a circuit including grounded battery, lefthand winding of relay 8, ring of plug 6 and of jack 5, through the substation loop, tip of jack 5 and plug 6, and right-hand winding of relay 8 to ground. Energization of relay 8' prevents the sruaervisory lamp 9 from lighting.

The operator then actuates the listening key 10 to connect the operators telephone set (not shown) in circuit so that the operator may converse with the calling subscriber to ascertain the number of the line with which connection is desired. Assuming that connection is desired with station E which terminates at the automatic exchange, the operator inserts calling plug 11 into jack 12 of the trunk circuit D. Trunk circuit D, connected to jack 12 in the manual switchboard, terminates in a line or trunk finder at the automatic exchange, and insertion of plug 11 in jack 12 bridges relay 4 across the trunk, thereby extending the calling line to an idle selector or connector in the manner Well known. Relay 4 will be energized thus preventing supervisory lamp 19 from lighting.

The operator then actuates the non-locking dialing key 20, whereupon a circuit for relay 21, including its left-hand winding and an alternate contact of key 20, is closed. Relay 21 attracts its armature thereby disconnecting the answering and calling ends of the link circuit and connecting the impulse sender S to the calling end. Relay 21 when operated is held locked up over a path including ground, its right-hand armature and front contact, and right-hand winding, conductor 22 and resistance 23 to grounded battery.

The operator may then actuate the im pulse sender S to send out impulses in accordance with the digits representing the number of the desired station E, thereby setting the switches in the automatic exchange in the well-known manner.

Upon completion of conversation, the subscriber at station A upon restoring the receiver tothe switchhook, causes the deenergization of supervisory relay 8 in the usual manner thereby lighting the supervisory lamp 9. The operator thereupon removes the plugs from their associated jacks.

A description will now be given of the method of disconnecting the impulse sender from the link circuit, with which it has been associated. A description will first be given of the manner in which automatic disconnection takes place. 7

As soon as key is released, a circuit is closed at its normal contact for the motor 24 which rotates the cams 30, 31 and 32. It will be understood that motor 24 may constantly rotate instead of rotating only when the impulse sender is connected as herein described. The circuit for motor 24 may be traced as follows: ground, normal contact of key 20, front contact and inner left-hand armature of relay 21, conductor 25, throughthe winding of motor 24 to grounded battery. A circuit is also completed for signal 47 in parallel with the'winding of motor 24 when key 20 is released, and this signal remains lighted until relay 21 isre'leased.

The arrangement of the automatic disconnect device is such that one set of contacts is always closed, and for the purpose of this description it will be assumed that" when the operator depresses non-locking key 20, the roller 33 rests on the operative surface of cam and the contacts associated with cam 30 are then closed, as shown inthe Therefore, when key 20 is released the circuit for motor 24 is closed drawing.

tact and inner left hand armature of relay 21, conductor 25, contacts 43 of impulse.

sender S (provided the operator does not immediately start dialing), back contact and inner right hand armature of relay 42, back contact and outer right-hand armature of relay 41, winding of relay 40, upper contacts of cam 30, to grounded battery. As soon as the impulse sender is actuated, con tacts 43 are opened and remain open until the dial returns to normal. Relay 40 there upon deenergizes.

If the operator has completed the sending of impulses or fails to operate the impulse sender S, contacts 43 thereof will be closed and the impulse sender will be automatically disconnected, after a certain interval of time has elapsed, for example, three or five seconds. This interval of time is the time required for the roller 33 to pass over the non-operative surface of cam 30.

As soon as roller 31 passes off the operative surface of cam 30, the contacts associated therewith return to normal, thereby opening the circuit over which relay 40 was energized. y 7

Relay 40 remains energized, however, by

current flowing through the winding of a slow-to-release relay 4:6. As soon as the contacts of cam' are opened, relay 46 therefore energizes in series with relay and remains energized until cam 30 has rotated sutficiently to bring roller 31 into engagement with the operative surface 50, when the contacts are again closed. When the lower contacts of cam 30 are closed, circuit is established'extending from ground through the lower contacts of cam 80, outer left-hand armature and front contact of relay 40, front contact and armature of relay 46, to conductor 22, resulting in the shunting of relay 21. Relay 4:6 is shunted as soon as the lower contacts of cam 30 are closed, and as this relay is of the slowto-release type it insures the grounding of conductor 22 before it releases its armature.

When relay 21 is shunted it deenergizes, thereby disconnecting the impulse sender S from the link circuit and restoring the continuity of the link circuit. Relav 21 in retracting its armatures interrupts the circuit for relay 40, motor 24 and signal 47, and the system is ready for the next call. If, when the next call is made the contacts of cam 31 or 32 are operated, the connecting relay 21 in the link circuit would be shunted in a manner similar to that described heretoiore. Three cams are shown in order that there may not be such a long interval between the closing of the contacts associated with the cams.

If the operator desires to use the impulse sender before automatic disconnection has taken place, the non-locking key, such as 20, of a second link circuit, such as C, may be actuated. Actuation of this key grounds conductor 22, thereby shunting the connecting relay 21 of the first link circuit B and completes a circuit for the connecting relay 21 of the second link circuit C.

What is claimed is:

1. In a telephone system, a connecting circuit including automatic switches, an im pulse sender for setting the switches, means for associating the impulse sender with the connecting circuit, and a timing device controlled by the impulse sender for automatically disassociating the impulse sender from the connecting circuit, after the lapse of a predetermined interval after the sender is restored to normal.

2. In a telephone system, a connecting circuit including automatic switches, an impulse sender for selectively operating the switches, manual means for associating the impulse sender with the connecting circuit, and means for automatically disassociating the impulse sender from the connecting circuit, said means being controlled independently of the switches and being effective after the lapse oi: apredetermined interval after the sender is restored to normal.

3. In a telephone system, a link circuit, automatic switches, an impulse sender for setting the switches, a relay associated with the link circuit adapted upon energization to connect the impulse sender with the link circuit, a key in said link circuit adapted upon actuating to energize said relay, and means for automatically deenergizing said relay, said means operating independently of the switches.

4c. In a telephone system, a plurality of connecting circuits, an impulse sender, means associated with one of said connecting circuits for connecting the impulse sender therewith, means for automatically disconnecting the impulse sender from the connecting circuit with which it has been connected, and means at each of the other connecting circuits for disconnecting the impulse sender from said first mentioned connecting circuit and transferring the impulse sender into connection with said other connecting circuit prior to automatic disconnection.

5. In a telephone system, a connecting circuit, including automatic switches, an impulse sender for setting said automatic switches, a relay adapted upon energization to connect said impulse sender with the connecting circuit, a locking circuit completed by said relay when energized, a key adapted upon actuation to complete a circuit for said relay, 2. second connecting circuit, a relay for said second connecting circuit, and a key associated with said second circuit adapted upon actuating to shunt the relay of the first mentioned connecting circuit and complete a circuit for the relay ot' the second mentioned connecting circuit.

6. In a telephone system, a connecting circuit including automatic switches, an impulse sender normally disconnected from said connecting circuit for setting the switches, a relay adapted upon energization to connect the impulse sender with the con necting circuit, and manual and automatic means for shunting said relay to cause its deenergization.

7. In a telephone system, a connecting circuit including automatic switches, an impulse sender for setting said switches, a signal associated with said circuit,akey adapted when momentarily depressed to connect said impulse sender with said connecting circuit, and for locking said sender to said circuit, a locking circuit for said signal closed by said key, and means for automatically disconnecting said impulse sender and interrupting said locking circuits.

8. In a telephone system, a connecting circuit including automatic switches, an impulse sender for setting said switches, a relay adapted to connect said impulse sender with the connecting circuit, a signal associated with said connecting circuit, a circuit for said signal completed by said relay when energized, a key for completing a circuit for energizing said relay, a second connecting circuit, a connecting relay therefor, a key associated with said second connecting circuit, and means operative upon theactuat-ion of the key of the second connecting circuit for interrupting the circuit of the first mentioned relay and for completing a circuit for the relay of the second connecting circuit.

9. In a telephone system, a plu'ality of link circuits, an impulse sender, means for connecting the impulse sender to any desired one of the link circuits, and means responsive to the actuation of the sender connecting means for automatically disconnecting the sender from the selected link circuit at a predetermined interval atter the connection thereof, irrespective of whether or not said sender has beenactuated.

' 10. I11 a telephone system, a link circuit, an impulse sender, means for connecting the impulse sender to the link. circuit,

switches controlled by said sender, and means for automatically disconnectingthe sender from the link circuit a predetermined time interval after the sender has been associated, said means operating independently of said switches.

11. In a telephone system, a plurality of cord circuits, a non-locking key for each cord circuit, a rotary impulse sender common to said cord circuits, means responsive to the actuation of one of said keys to connect the sender to the cord circuit containing the actuated key, and a timing device common to said cord circuits for automatically disconnecting said sender from said cord circuit, said device being effective to disconnect said sender irrespective of whether or not said sender is actuated.

12. In a telephonesystem, a plurality of cord circuits each terminating in a plug at each end, said plugs being normally interconnected, an impulse sender common to said cord circuits, a non-locking key for eachcord 7 associating the plugs of the cord circuit and for connecting the impulse sender to onset the plugs, and means local to the cord circuit for automatically disconnecting the sender therefrom.

13. In a telephone system, a plurality of cord circuits each comprising a pair of; talking conductors and terminating at each end in a plug, an impulse sender common to said cord circuits, a non-locking key for each cord circuit, means responsive to the actuation of the key of one of the cord circuits for rendering the talking conductors of the cord circuit discontinuous and for connecting the impulse sender to one of the plugs of the cord circuit, and means common to thecord'circuits for automatically disconnecting the impulse sender from the cord circuit taken for use.

14:. In a telephone system, a connecting circuit including automatic switches, an im-V pulse sender for setting the switches, and meansfor alloting said sender to a operator for a predetermined interval and for remov ing the sender from operative control of the operator after said interval has elapsed regardless of the number of setting operations completed by the operator. 7

15. In a telephone system, a connecting circuit including automatic switches, an impulse sender for setting theswitches, means for associating the impulse sender with the connecting circuit and-a timing'device controlled by the impulse sender :tor automatically disasso'ciating the impulse sender from the connecting circuitafter the lapse of a predetermined interval, and means for'preventing the disassociation to take place while a setting operation is in progress.

In witness whereof, I hereunto subscribe by name this 30th day of December A. D,

CHARLES W; KECKLEB. 

